No parasites in leeches?

Actually, I mean 'no pathogens transmitted to humans by leeches?,' but
that was too long.
I once read in an airline magazine that no leech is known to act as a
vector for a human disease. Is this true? Are any leeches vectors for
pathogens for other species?
--
Jim Gilliam
james_gilliam at ncsu.edu (preferred) or jfgzo at unity.ncsu.edu
Department of Zoology
North Carolina State University
Raleigh, NC 27695-7617